Rory McIlroy may have won the U.S. Open last month by eight shots at Congressional, but I have a feeling the pro golfer wouldn't be as happy if it weren't for something -- or should I say, someone -- seemingly unrelated: His old flame, Holly Sweeney. See, McIlroy broke up with Sweeney before the start of the 2011 season to "focus more on his game," but in a documentary that aired this past weekend on theBBC Northern Ireland, he said he realized he needed to win her back.

Why? Well, sure, there's the lovey-dovey part. These two crazy kids (he's 22 and she's 20!) have known each other for six years, and have been together (off and on, it seems) since he was 16 and she was 14, making them practically childhood sweethearts. But I'd also venture to guess that McIlroy realized that being with Sweeney wasn't just good for his heart. Their relationship's good for his game.

He explained to the BBC:

She keeps my feet on the ground and knows the things to say to me. She has been such a great support. She takes my mind off golf and everything else that is going on.

Keeping him grounded and preventing him from getting a big head about his success? Amazing! Definitely necessary! Especially in a sport where there's a lot of money to be made from endorsements, and someone as young and seemingly impressionable as McIlroy could easily get dragged away into cocky Tiger Woodsville.

Supporting his competitive edge? Yes! Holly didn't fly over to Congressional after she attended the Masters, because she was worried she might be a distraction. But she has attended multiple golf tournaments and even attended last year's Ryder Cup as his plus-one. She's obviously his number one fan, which is perfect! Victoria Beckham quality all-around!

Plus, taking his mind off of golf? Well, having a partner who takes your mind too far or too frequently off of golf (or any game you compete in professionally) is probably not helpful. But an athlete like McIlroy certainly needs someone to come home to and vent to about all those other headstrong players, and to help him de-stress and escape after a long, grueling day of playing 18 holes on the green.

See, McIlroy is so young, one might argue he doesn't need to settle down, the world is his oyster now, why does he need puppy love for his very own Joey Potter "holding him back"? But the opposite seems to be true. In fact, McIlroy told the Mirror that he attributes his U.S. Open win in part to Holly's support. Clearly, their love is at least one of the winning ingredients for his continued success in golf.